CNL-18-045, Clinch River, Voluntary Submittal Comparing Offsite Atmospheric Dispersion Using Vector and Scalar Wind Direction in Support of Early Site Permit Application

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Clinch River, Voluntary Submittal Comparing Offsite Atmospheric Dispersion Using Vector and Scalar Wind Direction in Support of Early Site Permit Application
ML18100A950
Person / Time
Site: Clinch River
Issue date: 04/09/2018
From: James Shea
Tennessee Valley Authority
To:
Document Control Desk, Office of New Reactors
References
CNL-18-045
Download: ML18100A950 (21)


Text

Tennessee Valley Authority, 1101 Market Street, Chattanooga, TN 37402 CNL-18-045 April 9, 2018 10 CFR 52, Subpart A ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Clinch River Nuclear Site NRC Docket No.52-047

Subject:

Voluntary Submittal Comparing Offsite Atmospheric Dispersion Using Vector and Scalar Wind Direction in Support of Early Site Permit Application for Clinch River Nuclear Site

Reference:

Letter from TVA to NRC, CNL-17-151, Revision 1 of Application for Early Site Permit for Clinch River Nuclear Site, dated December 15, 2017 By letter dated December 15, 2017 (Reference 1), Tennessee Valley Authority (TVA) submitted Revision 1 of the application for an early site permit (ESP) for Clinch River Nuclear Site. During a December 2017 public meeting, the Nuclear Regulatory Commission (NRC) requested clarification to ESP application, Part 2, Site Safety Analysis Report (SSAR),

Subsection 2.3.3, Onsite Meteorological Measurements Program, regarding the use of vector transport wind direction in calculating atmospheric dispersion for the Clinch River Nuclear Site. to this letter provides the response to the NRC question posed during the public meeting. Enclosure 2 to this letter provides markups of SSAR Subsection 2.3.1.3.6.2, Normal and Extreme Winter Precipitation Events and Subsection 2.3.1.4 Design Basis Dry- and Wet-Bulb Temperatures, and SSAR Tables 2.0-1, 2.3.4-2 through 2.3.4-8 and 2.3.4-11.

These changes are made to be consistent with the terminology in Interim Staff Guidance DC/COL-ISG-007 Assessment of Normal and Extreme Winter Precipitation Loads on the Roofs of Seismic Category I Structures.

The revised SSAR subsections and tables will be incorporated in a future revision of the ESP application.

U.S. Nuclear Regulatory Commission CNL-18-045 Page 2 April 9, 2018 There are no new regulatory commitments associated with this submittal. If any additional information is needed, please contact Dan Stout at (423) 751-7642.

I declare under penalty of perjury that the foregoing is true and correct. Executed on this 9th day of April 2018.

J. . Shea V ice President, Nuclear Regulatory Affairs and Support Services Enclosure

1. TVA Response to NRC Request on Use of Vector Wind Direction Values
2. Clinch River Nuclear Site Safety Analysis Report Revised Subsections 2.3.1.3.6.2, 2.3.1.4 and SSAR Tables 2.0-1 , 2.3.4-2 through 2.3.4-8 and 2.3.4-11.

cc (Enclosure) :

A. Fetter, Project Manager, Division of New Reactor Licensing , USNRC M. Sutton, Project Manager, Division of New Reactor Licensing, USNRC cc (without enclosure):

C. Haney, Regional Administrator, Region II, USNRC F. Akstulewicz, Director, Division of New Reactor Licensing, USNRC J. Colaccino, Branch Chief, Division of New Reactor Licensing , USNRC P. Vokoun, Project Manager, Division of New Reactor Licensing , USNRC T. Dozier, Project Manager, Division of New Reactor Licensing , USNRC M. M. Mcintosh, Regulatory Specialist, Eastern Regulatory Field Office, Nashville District, USACE

ENCLOSURE 1 TVA Response to NRC Request on Use of Vector Wind Direction Values During a December 2017 public meeting, NRC identified that the transport wind direction TVA used for development of atmospheric dispersion values in the Clinch River Early Site Permit Application (ESPA) is based on vector wind direction and did not conform with regulatory guidance. NRC requested TVA to explain how the methodology used follows regulatory guidance or provide justification for deviating from the guidance.

In the ESPA TVA identified compliance with Regulatory Guide (RG) 1.23, Meteorological Monitoring Programs for Nuclear Power Plants, which references ANSI/ANS-3.11-2005, Determining Meteorological Information at Nuclear Facilities. Section 5.3.1 of ANSI/ANS-3.11-2005 states that the transport wind direction for straight-line Gaussian models should be based on the scalar mean (or unit vector) wind direction. TVAs ESPA does use straight-line Gaussian models for the development of atmospheric dispersion values but the transport wind direction used in those models is based on vector wind direction. However, the use of scalar mean (or unit vector) wind direction for the transport wind direction for straight-line Gaussian models is a recommendation and not a requirement per the ANSI/ANS-3.11-2005 definition for should.

Therefore, TVA conforms with Section 5.3.1 of ANSI/ANS-3.11-2005 and RG 1.23.

However, TVA recognizes the recommendation in ANSI/ANS-3.11-2005 and has evaluated the use of vector and scalar wind direction as the transport wind direction for development of atmospheric dispersion values for the Clinch River Site. Analysis has shown that atmospheric dispersion values are greater in some directions and lower in others when comparing the different transport wind directions.

For the accidental gaseous release described in Site Safety Analysis Report (SSAR) Chapter 15, only the single limiting atmospheric dispersion value is used to compute dose. Both the vector and scalar wind direction analyses identify the west northwest (WNW) as the limiting direction. Additionally, the vector wind direction analysis WNW atmospheric dispersion value is larger than that for the scalar wind direction analysis. Therefore, for the accidental gaseous release, using vector wind direction for the development of atmospheric dispersion values is conservative.

For the normal gaseous release described in SSAR Chapter 11, the Maximally Exposed Individual (MEI) and population doses are evaluated. This analysis uses all of the different compass directions. Since scalar wind direction anaylsis values are greater in some directions and lower in others, the dose was analyzed. This analysis shows that the doses computed using the vector wind direction are greater than those computed using the scalar wind direction input.

Therefore, it is concluded, for the Clinch River Site normal dose evaluations, that the use of vector wind direction is conservative compared to the use of scalar wind direction.

Based on the information provided above, TVA has evaluated the recommendation in ANSI/ANS-3.11-2005 to use scalar mean (or unit vector) wind direction as the transport wind direction for straight-line Gaussian models and concluded that the existing analysis included in the ESPA, which is based on vector wind direction, is conservative and remains the basis of the ESPA.

CNL-18-045 E1-1

ENCLOSURE 2 Clinch River Nuclear Site Safety Analysis Report Revised Subsections 2.3.1.3.6.2, 2.3.1.4 and SSAR Tables 2.0-1, 2.3.4-2 through 2.3.4-8 and 2.3.4-11 SSAR Table 2.0-1 is being revised as indicated. Strikethroughs indicate text to be deleted. Underlines indicate text to be added.

CNL-18-045 E2-1

Table 2.0-1 Site Characteristics (a)

Characteristic/Parameter Site-Specific Value Description SSAR Section Geography and Demography Exclusion Area Boundary Clinch River Property The area surrounding the reactors, in 2.1.1 (EAB) Boundary which the reactor licensee has the authority to determine all activities, including exclusion or removal of personnel and property from the area.

Low Population Zone 1 mi from CRN Site center The area immediately surrounding the 2.1.3.4 point exclusion area which contains residents, the total number and density of which are such that there is a reasonable probability that appropriate protective measures could be taken in their behalf in the event of a serious accident.

Population Center Distance 4.8 mi (southeast) The distance from the site center point 2.1.3.5 to the nearest boundary of a densely populated center containing more than about 25,000 residents.

Meteorology and Hydrology Winter Precipitation 100-yr Snowpack 12.2 psf The weight of the 100-year return 2.3.1.3.6.2 period snowpack (to be used in determining normal precipitations loads for roofs).

48-hour Probable Maximum 23.5 in Probable Maximum Precipitation 2.3.1.3.6.2 Winter Precipitation (PMP) during the winter months (to be (PWMP) used in conjunction with the 100-yr snowpack in determining normal precipitation loads for roofs).

Normal Winter Precipitation 21.9 psf The maximum ground-level weight 2.3.1.3.6.2 Event (lb/ft2) of the 1) 100-year return snowpack (snow cover), 2) historical snowpack (snow cover), 3) 100-year return 2-day snowfall event, or 4) historical maximum 2-day snowfall event.

Extreme Frozen Winter 21.9 psf The maximum ground level weight 2.3.1.3.6.2 Precipitation Event (lb/ft2) of the 1) 100-year return 2-day snowfall event or 2) historical maximum 2-day snowfall event.

CNL-18-045 E2-2

Table 2.0-1 Site Characteristics (a)

Characteristic/Parameter Site-Specific Value Description SSAR Section Extreme Liquid Winter Equivalent to the 48-hour The extreme liquid winter precipitation 2.3.1.3.6.2 Precipitation Event (48-hour PWMP 23.5 in event is defined as the theoretically Probable Maximum Winter greatest ground-level depth of Precipitation (PMWP)) precipitation (in inches of water) for a 48-hour period that is physically possible over a 25.9 square kilometer (10 square mile) area at a particular geographical location during those months with the historically highest snowpacks.

Potential for Frazil Ice in N/A Potential for accumulated ice 2.4.7 Ultimate Heat Sink (UHS) formation in the UHS Water Storage Water Storage Facility Facility in a turbulent flow condition.

Maximum Rainfall Rate 18.8 in/hr PMP for 1-hour and for 5-minute 2.3.1.3.3 6 in/5-minutes durations at the site estimated from Hydro-Meteorological Report HMR-52.

Maximum Flood 799.9 ft NGVD29 (799.5 ft Predicted maximum flood level 2.4.2, 2.4.3, and (or Tsunami) NAVD88) (including wave run-up) from external 2.4.10

-Still water events, not including local PMP.

6.1 ft (wind-wave) 806.0 ft NGVD29 (805.6 ft NAVD88)

-Combined Maximum Ground Water 816.1 ft NAVD88 Maximum groundwater level under 2.4.12 deep foundation structures in power block area.

Basic Wind Speed 96.3 mph for a 3-second Wind velocity at 33 ft above ground for 2.3.1.3.2 gust Exposure Category C associated with a 100-year return period in the site area.

Historical Maximum Wind 87 mph for a 3-second gust Wind velocity at 33 ft above ground 2.3.1.3.2 Speed 73 mph fastest mile associated with the most severe hurricane wind that has been historically observed in the site region.

Design-Basis Hurricane 130 mph for a 3-second The resulting windspeed for nominal 2.3.1.3.5 Windspeed gust 3-second peak-gust values at a height of 33 ft in flat open terrain.

Tornado Maximum Pressure Drop 1.2 psi Decrease in ambient pressure from 2.3.1.3.4 normal atmospheric pressure at the site due to passage of a tornado having a probability of occurrence of 10-7 per year.

Maximum Rotational Speed 184 mph Rotation component of maximum wind 2.3.1.3.4 speed at the site due to passage of a tornado having a probability of

-7 occurrence of 10 per year.

CNL-18-045 E2-3

Table 2.0-1 Site Characteristics (a)

Characteristic/Parameter Site-Specific Value Description SSAR Section Maximum Translational 46 mph Translation component of maximum 2.3.1.3.4 Speed wind speed at the site due to the movement across the ground of a tornado having a probability of

-7 occurrence of 10 per year.

Maximum Wind Speed 230 mph Sum of the maximum rotational and 2.3.1.3.4 translational wind speed components at the site due to passage of a tornado having a probability of occurrence of 10-7 per year.

Radius of Maximum 150 ft Distance from the center of the 2.3.1.3.4 Rotational Speed tornado at which the maximum rotational wind speed occurs at site due to passage of a tornado having a probability of occurrence of 10-7 per year.

Rate of Pressure Drop 0.5 psi/s Maximum rate of pressure drop at site 2.3.1.3.4 due to passage of a tornado having a probability of occurrence of 10-7 per year.

Site Characteristic Site characteristic wet bulb and dry 2.3.1.4 Ambient Air Temperatures bulb temperatures associated with the listed exceedance values and the 100-year return period.

Maximum Dry Bulb The maximum dry-bulb temperature Temperature with that has existed at the site for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> Maximum Wet Bulb or more combined with the maximum Temperature wet-bulb temperature that exists in that population of dry-bulb temperatures.

95% Annual Exceedance 30°F Dry Bulb 5% Annual Exceedance 85°F Dry Bulb 71.8°F Coincident Wet Bulb 2% Annual Exceedance 90°F Dry Bulb 73.7°F Coincident Wet Bulb 1% Annual Exceedance 92°F Dry Bulb 74.2°F Coincident Wet Bulb 0.4% Annual Exceedance 95°F Dry Bulb 74.9°F Coincident Wet Bulb 0% Annual Exceedance 105°F Dry Bulb 74.6°F Coincident Wet Bulb 100-Year Return Period 107°F Dry Bulb 73.1°F Coincident Wet Bulb Maximum Non-Coincident The maximum historic wet-bulb Wet Bulb Temperature temperature recorded for 2 or more hours.

2% Annual Exceedance 75.7°F 1% Annual Exceedance 76.7°F 0.4% Annual Exceedance 77.6°F CNL-18-045 E2-4

ENCLOSURE 2 Clinch River Nuclear Site Safety Analysis Report Revised Subsections 2.3.1.3.6.2, 2.3.1.4 and SSAR Tables 2.0-1, 2.3.4-2 through 2.3.4-8 and 2.3.4-11 The following paragraphs of SSAR Subsection 2.3.1.3.6.2 are being revised as indicated.

Strikethroughs indicate text to be deleted. Underlines indicate text to be added.

CNL-18-045 E2-5

2.3.1.3.6.2 Normal and Extreme Winter Precipitation Events Snowpack, as used in this section, is defined as a layer of snow and/or ice on the ground surface, and is usually reported daily, in inches, by the NWS at all first order weather stations.

Historical snowpack and snowfall were developed by reviewing data from 1st order NWS stations and the cooperative network.

From Figure 7-1 of American Society of Civil Engineers (ASCE) Standard No. 7-05, the 50-year mean recurrence interval snowpack for the Oak Ridge area is determined to be 10 pounds per square foot (psf). Converting this to a 100-year return period snowpack, using the 1.22 adjustment factor presented in Table C7-3 of ASCE 7-05, the 100-year return period snowpack is determined to be 12.2 psf.

The maximum reported snow depth at Chattanooga, TN (Reference 2.3.1-2), the highest snow depth at a nearby NWS station, was used to estimate the weight of the maximum historic snow pack at the CRN Site. The greatest snow depth reported during the 77-year period of record (1938-2014) for Chattanooga, was 19 inches in March 1993. Interim Staff Guidance (ISG) on Assessment of Normal and Extreme Winter Precipitation Loads on the Roofs of Seismic Category I Structures (ISG-7) (Reference 2.3.1-38), provides an algorithm (below) for converting historical maximum snowpack depth to a ground snow load Equation 2.3.1-3 Where, D is the snowpack depth in inches and L is the resulting snow load in psf.

Using the 19-inch snow depth for Chattanooga gives a snow load of 15.3 psf for the maximum historical snowpack.

The 100-year return period snowfall event is given in the United States Snow Climatology data provided by the National Climatic Data Center. Based on this data, the 48-hour 100-year return snowfall event for Oak Ridge is 15.3 inches and 21.1 inches for Knoxville. The historical maximum snowfall event for a 48-hour period was determined to be 28 inches recorded in Westbourne, TN from February 19, 1960 to February 21, 1960 (Reference 2.3.1-39). The equation below from ISG-7 was used to determine the snow load due to the 48-hour 100-year return period snowfall event and the historical maximum snowfall event.

L = 0.15 x S x 5.2 Equation 2.3.1-4 Where L is the snow load in psf and S is the Snowfall depth in inches.

Using the maximum 100-year return snowfall event of 21.1 inches results in a snow load of 16.5 psf. Using a 28 inch historical maximum snowfall event for a 48-hour period results in a snow load of 21.9 psf.

The Normal Winter Precipitation Event, defined as the maximum ground-level weight (lb/ft2) of the 1) 100-year snowpack (snow cover), 2) historical snowpack (snow cover), 3) 100-year return 2-day snowfall event, or 4) historical maximum 2-day snowfall event, is determined to be 21.9 psf. The Extreme Frozen Winter Precipitation Event, defined as the maximum of the 1) 100-year return 2-day snowfall event or 2) historical maximum 2-day snowfall event, is also determined to be 21.9 psf.

CNL-18-045 E2-6

ENCLOSURE 2 Clinch River Nuclear Site Safety Analysis Report Revised Subsections 2.3.1.3.6.2, 2.3.1.4 and SSAR Tables 2.0-1, 2.3.4-2 through 2.3.4-8 and 2.3.4-11 The following paragraphs of SSAR Subsection 2.3.1.4 are being revised as indicated.

Strikethroughs indicate text to be deleted. Underlines indicate text to be added.

CNL-18-045 E2-7

From Hydro-Meteorological Report HMR-53, NUREG/CR-1486, (Reference 2.3.1-32) the 48-hour Probable Maximum Winter Precipitation (PMWP) (January through March) for a 10 square-mile area is estimated to be 23.5 inches by logarithmic interpolation. The March PMWP was utilized since the historically highest snowpack occurred in March 1993. The 48-hour PMWP is equivalent to the Extreme Liquid Winter Precipitation Event.

2.3.1.4 Design Basis Dry- and Wet-Bulb Temperatures This section provides ambient temperature and humidity statistics for use in establishing heat loads for the design of normal plant heat sink systems, post-accident containment heat removal systems, and plant heating, ventilating, and air conditioning systems. The following parameters have been calculated:

maximum dry-bulb temperatures at 0%, 0.4%, 1%, 2%, 5%, and 95%, 98%, 99%, 99.6%,

and 100% annual exceedance levels, maximum coincident wet-bulb temperatures at 0%, 0.4%, 1%, 2%, and 5%, and 100%

annual exceedance levels, maximum non-coincident wet-bulb temperature at 0%, 0.4%, 1%, and 2%, 5%, 95%, 98%,

99%, and 99.6% annual exceedance levels, minimum dry-bulb temperature at 0%, 0.4%, 1%, and 2% annual exceedance levels, 100-year return maximum dry-bulb, coincident wet-bulb, and non-coincident wet-bulb, and minimum dry-bulb temperatures,.

100-year return minimum dry-bulb and wet-bulb temperature.

Meteorological data from the Chattanooga Lovell Airport was obtained from the National Oceanic and Atmospheric Administration (NOAA) NCDC for use in determining extreme values.

This data is the best available long-term data record because the data record for Oak Ridge is incomplete (data gap between 1985 and 1999). The ambient design temperatures required for the site envelope parameters are based on the criteria in the EPRI ALWR Utility Requirement Document (URD) [Reference 2.3.1-33], Table 1.2-6, and various design parameters as required by NRC Regulatory Guide 1.27 and SRP 2.3.1. While each of these documents sets forth various criteria, all evaluations are conducted on either dry-bulb or wet-bulb temperature. SRP 2.3.1 requires the following data be provided:

Ambient temperature and humidity statistics (e.g., 2% and 1% annual exceedance and 100-year maximum dry-bulb temperature and coincident wet bulb temperature; 2% and 1%

annual exceedance and 100-year maximum wet bulb temperature (non-coincident); 98%

and 99% annual exceedance and 100-year minimum dry-bulb temperature) for use in establishing heat loads for the design of normal plant heat sink systems, post-accident containment heat removal systems, and plant heating, ventilating, and air conditioning systems.

However, additional values were determined in accordance with the EPRI URD.

Sixty-six years of raw climatological data were obtained from NOAA/NCDC for the Chattanooga Lovell Airport. This data set contains hourly measurements of dry-bulb and dewpoint temperature records, amongst several other meteorological variables. This data was used to calculate the various exceedance temperatures. Results of the ambient design temperature CNL-18-045 E2-8

ENCLOSURE 2 Clinch River Nuclear Site Safety Analysis Report Revised Subsections 2.3.1.3.6.2, 2.3.1.4 and SSAR Tables 2.0-1, 2.3.4-2 through 2.3.4-8 and 2.3.4-11 SSAR Tables 2.3.4-2 through 2.3.4-8 are being revised as indicated. Strikethroughs indicate text to be deleted. Underlines indicate text to be added.

CNL-18-045 E2-9

Table 2.3.4-2 Joint Frequency Distribution (Hours) of Wind Speed and Direction by Atmospheric Stability Class - Stability Class A June 1, 2011 - May 31, 2013 WIND SPEED (MPH)

WIND DIRECTION >0.50 >1.10 >1.70 >2.20 >2.80 >3.40 >4.50 >6.70 >8.90 >11.20 >13.40 CALM 0.50 >18.00 TOTAL 1.10 1.70 2.20 2.80 3.40 4.50 6.70 8.90 11.20 13.40 18.00 N 0 0 0 1 0 3 3 9 16 2 0 0 0 0 34 NNE 0 0 0 1 1 4 10 23 23 0 0 0 0 0 62 NE 0 0 0 0 3 5 4 22 37 5 0 0 0 0 76 ENE 0 0 0 2 1 2 3 13 19 9 0 0 0 0 49 E 0 0 0 0 1 0 0 7 4 0 0 0 0 0 12 ESE 0 0 0 0 3 0 0 3 3 0 0 0 0 0 9 SE 0 0 0 0 0 2 0 1 0 0 0 0 0 0 3 SSE 0 0 0 1 0 0 1 0 2 1 0 0 0 0 5 S 0 0 0 0 2 0 0 0 0 0 0 0 0 0 2 SSW 0 0 0 1 1 0 0 1 0 0 0 0 0 0 3 SW 0 0 0 0 1 1 1 1 1 1 0 0 0 0 6 WSW 0 0 0 1 1 3 0 8 9 9 2 0 0 0 33 W 0 0 0 0 0 1 1 4 14 6 4 4 1 0 35 WNW 0 0 0 0 0 0 0 1 9 18 5 3 1 0 37 NW 0 0 0 1 2 0 1 6 21 48 23 4 0 0 106 NNW 0 0 0 1 0 1 0 5 9 4 0 0 0 0 20 SUBTOTAL 0 0 0 9 16 22 24 104 167 103 34 11 2 0 492 Notes:

Wind speed, direction measured at 10 meters (32.8 feet); mean wind speed = 5.73 mph.

CNL-18-045 E2-10

Table 2.3.4-3 Joint Frequency Distribution (Hours) of Wind Speed and Direction by Atmospheric Stability Class - Stability Class B June 1, 2011 - May 31, 2013 WIND SPEED (MPH)

>0.50 >1.10 >1.70 >2.20 >2.80 >3.40 >4.50 >6.70 >8.90 >11.20 >13.40 WIND DIRECTION CALM 0.50 1.10 1.70 2.20 2.80 3.40 4.50 6.70 8.90 11.20 13.40 18.00 >18.00 TOTAL N 0 0 0 0 1 3 7 9 9 0 0 0 0 0 29 NNE 0 0 0 0 0 1 12 20 5 0 0 0 0 0 38 NE 0 0 0 0 1 8 12 24 36 3 0 0 0 0 84 ENE 0 0 0 0 0 5 7 10 16 1 0 0 0 0 39 E 0 0 0 0 0 0 5 12 8 0 0 0 0 0 25 ESE 0 0 0 0 0 1 1 6 1 0 0 0 0 0 9 SE 0 0 0 0 0 1 2 1 0 0 0 0 0 0 4 SSE 0 0 0 0 0 0 2 7 5 0 0 0 0 0 14 S 0 0 0 0 0 0 3 5 10 0 1 2 0 0 21 SSW 0 0 0 0 0 0 1 2 4 1 0 0 0 0 8 SW 0 0 0 0 0 0 2 11 13 4 0 0 0 0 30 WSW 0 0 0 0 0 1 8 23 41 18 5 1 0 0 97 W 0 0 0 0 0 1 3 18 14 2 1 2 1 0 42 WNW 0 0 0 0 0 0 4 7 20 17 6 2 1 0 57 NW 0 0 0 0 0 0 5 12 26 31 10 1 0 0 85 NNW 0 0 0 0 0 0 4 10 11 3 0 0 0 0 28 SUBTOTAL 0 0 0 0 2 21 78 177 219 80 23 8 2 0 610 Notes:

Wind speed, direction measured at 10 meters (32.8 feet); mean wind speed = 5.17 mph.

CNL-18-045 E2-11

Table 2.3.4-4 Joint Frequency Distribution (Hours) of Wind Speed and Direction by Atmospheric Stability Class - Stability Class C June 1, 2011 - May 31, 2013 WIND SPEED (MPH)

>0.50 >1.10 >1.70 >2.20 >2.80 >3.40 >4.50 >6.70 >8.90 >11.20 >13.40 WIND DIRECTION CALM 0.50 1.10 1.70 2.20 2.80 3.40 4.50 6.70 8.90 11.20 13.40 18.00 >18.00 TOTAL N 0 0 0 0 3 7 15 6 13 0 0 0 0 0 44 NNE 0 0 0 1 0 13 12 21 3 0 0 0 0 0 50 NE 0 0 0 1 6 13 23 26 10 1 0 0 0 0 80 ENE 0 0 0 1 5 8 12 16 9 1 0 0 0 0 52 E 0 0 0 1 2 4 11 12 5 0 0 0 0 0 35 ESE 0 0 0 0 3 6 6 9 3 0 0 0 0 0 27 SE 0 0 0 0 2 8 2 6 5 0 0 0 0 0 23 SSE 0 0 0 0 1 3 10 4 2 1 0 2 0 0 23 S 0 0 0 0 1 4 4 13 15 4 2 1 0 0 44 SSW 0 0 0 0 1 6 9 12 12 3 0 0 0 0 43 SW 0 0 0 0 1 10 14 26 43 12 0 0 0 0 106 WSW 0 0 0 0 0 9 33 60 70 13 5 1 0 0 191 W 0 0 0 0 2 4 27 34 35 7 6 3 0 0 118 WNW 0 0 0 0 1 4 10 21 26 15 4 2 0 0 83 NW 0 0 0 0 0 1 11 14 38 20 7 0 0 0 91 NNW 0 0 0 0 2 4 4 9 8 4 3 0 0 0 34 SUBTOTAL 0 0 0 4 30 104 203 289 297 81 27 9 0 0 1044 Notes:

Wind speed, direction measured at 10 meters (32.8 feet); mean wind speed = 4.54 mph.

CNL-18-045 E2-12

Table 2.3.4-5 Joint Frequency Distribution (Hours) of Wind Speed and Direction by Atmospheric Stability Class - Stability Class D June 1, 2011 - May 31, 2013 WIND SPEED (MPH)

WIND >0.50 >1.10 >1.70 >2.20 >2.80 >3.40 >4.50 >6.70 >8.90 >11.20 >13.40 DIRECTION CALM 0.50 1.10 1.70 2.20 2.80 3.40 4.50 6.70 8.90 11.20 13.40 18.00 >18.00 TOTAL N 0 1 14 57 33 27 17 22 21 2 0 0 0 0 194 NNE 0 0 6 53 49 39 25 42 11 0 0 0 0 0 225 NE 0 0 16 41 55 65 77 82 71 3 1 0 0 0 411 ENE 0 0 12 42 38 59 54 71 68 8 1 1 0 0 354 E 0 1 8 19 42 33 29 21 10 1 0 0 0 0 164 ESE 0 0 6 19 15 15 13 12 5 0 0 0 0 0 85 SE 0 0 6 10 17 21 19 10 1 1 0 1 0 0 86 SSE 0 0 4 9 12 25 11 12 10 4 7 1 0 0 95 S 0 0 3 13 23 37 44 51 56 30 25 7 3 0 292 SSW 0 1 8 16 23 39 41 44 49 6 0 0 0 0 227 SW 0 0 2 14 38 59 75 123 116 29 4 0 0 0 460 WSW 0 0 0 16 54 95 93 219 254 83 29 8 0 0 851 W 0 0 13 34 48 79 87 132 99 46 31 20 1 0 590 WNW 0 0 10 43 42 72 49 98 140 79 36 9 4 0 582 NW 0 0 19 48 43 58 48 85 139 75 35 6 0 0 556 NNW 0 0 16 41 30 33 30 27 35 11 4 0 0 0 227 SUBTOTAL 0 3 143 475 562 756 712 1051 1085 378 173 53 8 0 5399 Notes:

Wind speed, direction measured at 10 meters (32.8 feet); mean wind speed = 4.01 mph.

CNL-18-045 E2-13

Table 2.3.4-6 Joint Frequency Distribution (Hours) of Wind Speed and Direction by Atmospheric Stability Class - Stability Class E June 1, 2011 - May 31, 2013 WIND SPEED (MPH)

WIND >0.50 >1.10 >1.70 >2.20 >2.80 >3.40 >4.50 >6.70 >8.90 >11.20 >13.40 DIRECTION CALM 0.50 1.10 1.70 2.20 2.80 3.40 4.50 6.70 8.90 11.20 13.40 18.00 >18.00 TOTAL N 0 0 86 73 27 14 9 3 3 0 0 0 0 0 215 NNE 0 3 84 58 29 14 4 3 1 0 0 0 0 0 196 NE 0 3 79 63 30 27 16 24 7 1 1 0 0 0 251 ENE 0 2 57 60 34 39 22 17 12 1 0 0 0 0 244 E 0 2 67 55 29 23 15 7 7 0 0 0 0 0 205 ESE 0 5 54 58 18 10 9 3 2 0 0 0 0 0 159 SE 0 1 46 68 16 12 5 2 2 1 0 0 0 0 153 SSE 0 0 43 32 21 19 11 11 12 4 2 0 0 0 155 S 0 2 22 43 34 24 21 12 8 7 0 0 0 0 173 SSW 0 0 18 41 28 17 17 16 5 1 1 0 0 0 144 SW 0 1 26 44 30 35 33 16 12 5 0 0 0 0 202 WSW 0 2 39 52 44 51 54 49 39 12 3 0 0 0 345 W 0 2 54 63 65 65 47 59 50 8 1 1 1 0 416 WNW 0 3 90 118 60 48 35 54 68 29 5 2 0 0 512 NW 0 3 111 96 36 40 29 46 57 20 4 0 0 0 442 NNW 0 2 82 66 21 24 11 16 4 0 0 0 0 0 226 SUBTOTAL 0 31 958 990 522 462 338 338 289 89 17 3 1 0 4038 Notes:

Wind speed, direction measured at 10 meters (32.8 feet); mean wind speed = 2.32 mph.

CNL-18-045 E2-14

Table 2.3.4-7 Joint Frequency Distribution (Hours) of Wind Speed and Direction by Atmospheric Stability Class - Stability Class F June 1, 2011 - May 31, 2013 WIND SPEED (MPH)

WIND >0.50 >1.10 >1.70 >2.20 >2.80 >3.40 >4.50 >6.70 >8.90 >11.20 >13.40 DIRECTION CALM 0.50 1.10 1.70 2.20 2.80 3.40 4.50 6.70 8.90 11.20 13.40 18.00 >18.00 TOTAL N 0 14 90 12 1 1 1 0 0 0 0 0 0 0 119 NNE 0 14 83 23 2 3 2 1 0 0 0 0 0 0 128 NE 0 10 97 24 2 2 0 0 0 0 0 0 0 0 135 ENE 0 17 138 29 14 5 2 0 1 0 0 0 0 0 206 E 0 14 187 74 15 2 2 0 1 0 0 0 0 0 295 ESE 0 15 185 87 22 2 4 0 0 0 0 0 0 0 315 SE 0 14 153 76 15 3 1 1 0 0 0 0 0 0 263 SSE 0 5 79 32 8 4 1 1 0 0 0 0 0 0 130 S 0 11 49 29 6 5 3 2 1 0 0 0 0 0 106 SSW 0 7 32 23 11 0 2 0 2 0 0 0 0 0 77 SW 0 2 38 26 12 4 2 3 0 0 0 0 0 0 87 WSW 0 5 42 24 10 3 8 3 1 0 0 0 0 0 96 W 0 1 91 39 15 17 4 5 3 0 0 0 0 0 175 WNW 0 10 131 101 33 9 4 6 4 2 0 0 0 0 300 NW 0 16 156 59 15 13 3 2 1 0 0 0 0 0 265 NNW 0 14 99 25 3 2 0 0 0 0 0 0 0 0 143 SUBTOTAL 0 169 1650 683 184 75 39 24 14 2 0 0 0 0 2840 Notes:

Wind speed, direction measured at 10 meters (32.8 feet); mean wind speed = 1.16 mph.

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Table 2.3.4-8 Joint Frequency Distribution (Hours) of Wind Speed and Direction by Atmospheric Stability Class - Stability Class G June 1, 2011 - May 31, 2013 WIND SPEED (MPH)

WIND >0.50 >1.10 >1.70 >2.20 >2.80 >3.40 >4.50 >6.70 >8.90 >11.20 >13.40 DIRECTION CALM 0.50 1.10 1.70 2.20 2.80 3.40 4.50 6.70 8.90 11.20 13.40 18.00 >18.00 TOTAL N 0 10 34 3 2 0 0 0 0 0 0 0 0 0 49 NNE 0 5 27 1 0 0 0 1 0 0 0 0 0 0 34 NE 0 7 31 5 2 1 1 0 0 0 0 0 0 0 47 ENE 0 10 103 15 5 2 0 1 0 0 0 0 0 0 136 E 0 27 226 53 13 0 0 0 1 0 0 0 0 0 320 ESE 0 32 372 164 14 0 0 1 0 0 0 0 0 0 583 SE 0 21 334 139 7 1 2 1 0 0 0 0 0 0 505 SSE 0 17 209 41 4 1 0 0 0 0 0 0 0 0 272 S 0 15 101 21 5 0 0 0 0 0 0 0 0 0 142 SSW 0 5 73 19 5 1 0 1 0 1 0 0 0 0 105 SW 0 9 46 13 2 1 0 1 0 0 0 0 0 0 72 WSW 0 7 94 21 5 0 1 0 0 0 0 0 0 0 128 W 0 8 104 56 2 4 2 1 1 0 0 0 0 0 178 WNW 0 15 120 65 16 5 2 2 0 0 0 0 0 0 225 NW 0 9 73 19 1 1 0 0 0 0 0 0 0 0 103 NNW 0 12 40 6 0 0 0 0 0 0 0 0 0 0 58 SUBTOTAL 0 209 1987 641 83 17 8 9 2 1 0 0 0 0 2957 Notes:

Wind speed, direction measured at 10 meters (32.8 feet); mean wind speed = 1.00 mph.

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ENCLOSURE 2 Clinch River Nuclear Site Safety Analysis Report Revised Subsections 2.3.1.3.6.2, 2.3.1.4 and SSAR Tables 2.0-1, 2.3.4-2 through 2.3.4-8 and 2.3.4-11 SSAR Table 2.3.4-11 is being revised as indicated. Strikethroughs indicate text to be deleted. Underlines indicate text to be added.

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Table 2.3.4-11 Distances and Elevations for the EAB and LPZ in the 16 Wind Direction Sectors Distance from Effluent Release Boundary to Analytical EAB LPZ Distance Wind Direction Sector (feet) (meters) (miles) (meters)

S 1100 335 1 1609 SSW 1100 335 1 1609 SW 1100 335 1 1609 WSW 1100 335 1 1609 W 1100 335 1 1609 WNW 1100 335 1 1609 NW 1100 335 1 1609 NNW 1100 335 1 1609 N 1100 335 1 1609 NNE 1100 335 1 1609 NE 1100 335 1 1609 ENE 1100 335 1 1609 E 1100 335 1 1609 ESE 1100 335 1 1609 SE 1100 335 1 1609 SSE 1100 335 1 1609 Notes:

The Effluent Release Boundary includes the nuclear island, which consists of the reactor service building and associated buildings that are potential sources of radioactive releases.

The low population zone (LPZ) was determined as an area with a 1-mi (1609 m) radius from the site center point.

EAB = exclusion area boundary CNL-18-045 E2-18